For those who missed it in the other thread:
System requirements are here:
http://nwn.bioware.com/about/requirements.html
Required
Pentium® II 450 MHz or AMD K6- 450 MHz
Windows 98/ME/2000SP2/XP
96 MB RAM
1.2 GB HD space free
8X CD-ROM
DirectX® version 8.1
16 MB TNT2-class OpenGL 1.2 compliant video card
DirectX® certified sound card
56k Modem (if using modem)
Recommended
Pentium® III 800 MHz or AthlonTM 800 MHz
Windows 98/ME/2000SP2/XP
256 MB RAM
2.0 GB HD space free
8X CD-ROM
DirectX® version 8.1
NVIDIA GeForce 2/ATI Radeon
DirectX® certified sound card
56k Modem (if using modem)
Those are the Windows requirements. They plan to release Windows/Mac/Linux all in the same box.